This invention relates to a mixer valve comprising a fixed hard material plaque having passage openings communicating with two liquid feeding pipes, control means, a plastic material slide connected to said control means, and at least one movable hard material plaque which is rigidly connected to said control slide and cooperates through a portion of its peripheral edge with the passage openings of said fixed plaque in order to control the delivered liquid flow rate and the mixing ratio of the two liquids fed to the valve.
Such mixer valves are widely employed for household and sanitary appliances, for the delivery of mixed hot and cold water coming from respective feeding pipes. In some cases, these mixer valves have the particular disadvantage of producing a noise, which arises when the passage of one of the incoming liquids is highly throttled. In these conditions, in fact, the throttled flow reaches a high speed and a high turbulence, which give rise to vibrations both directly and because of the impact of the flow against surfaces of the valve. On the other hand, the configuration of the valves of the referred type does not allow a useful installation of prethrottling means of one of the already known types which are employed in other types of valves in order to solve similar problems.